Ultraviolet lamp



June 8, 1937. c. F. LORENZ 2,032,963

ULTRAVIOLET LAMP Filed June 12, 1930 2 Sheets-Sheet 1 32' INVENTOR C. ELORfi/VZ ATTORNEY June 8, 1937. c. FfLoRENz 2,082,963

ULTRAVIOLET LAMP Filed June 12, 1930 2 Sheets-Sheet 2 INVENTOR C./-TLOF?E/VZ ATTORN Patented June 8 1937 UNITED STATES ULTRAVIOLET L Charles F. Lorenz, East Orange, N. 3., assigno f,

by mesne assignments, to Westinghouse E180! trio and Manufacturing Company, East Pittsburgh, Pa., a corporation of Pennsylvania Application June 12, 1930, Serial No. 460,587

20 Claims.

This invention relates to a lamp for the production of ultra-violet radiations and more particularly to a gaseous conductionlamp yielding a spectrum relatively rich in ultra-violet light.

Ultra-violet light has long been recognized as beneficial in therapy, but heretofore a greater number of the available devices for producing ultra-violet light have been of such character as to require relatively'high operating current and were difficult to control, usually necessitating expensive auxiliary equipment. For this reason a general application of the ultra-violet source of radiations, as for example in work rooms, or generally in living rooms has been restricted. The relatively high cost of equipment made it impractical for obtaining even a mild source of ultraviolet light, although the benefits resulting from the same have been long recognized.

It is one of the purposes of the present invention to provide an ultra-violet source of radiationwhich may be used in living rooms of dwellings and which will give an amount of ultra-violet as near as possible the equal of natural sun- In accomplishing the above end the present invention provides a device which may be used on the ordinary commercial lighting lines of 110 to 220 volts in the absence of expensive equipment such as transformers or the like.

A further purpose of the invention is to provide a source of ultra-violet light combined with a source of illumination produced by means of a coiled tungsten filament which in itself emanates a certain amount of ultra-violet light.

By reason of the present invention wherein a source of ultra-violet light is combined with a source of illumination, a structure may be provided wherein both sources may be combined in a unitary structure capable of being applied directly to the commercial line voltages.

In producing the present invention a sealed envelope is provided and divided into two compartments of substantially tubular form. These compartments may preferably be disposed'in concentric relation and a common electrical circuit may be employed for supplying electrical energy to light giving elements in one compartment and other elements for producing a source of ultraviolet light in the other compartment.

Although an embodiment of the present inven-- tion may be so constructed as to provide a source of ultra-violet light and may be enclosed in a suitable glass for transmitting ultraviolet radiations, as for example, a glass known in the trade as Corex, the invention is also useful in providing a lighting unit which will imitate daylight violet transmitting material. By means of the arrangement shown wherein the compartments constituting an enclosing envelope are disposed in close and concentric arrangement, the unit resulting has the advantage of being freefrom shadow contrasts and especially suitable for use p in a reflector.

Briefly the invention comprises an enclosing envelope having a compartment in which two coiled filaments are disposed. These filaments are connected in series in the electrical circuit of the lamp which includes a heater element dis posed in the other compartment which latter compartment contains a mercury vapor environment. The pressure of the mercury vapor depends on the temperature of operation. Ordinarily this will be fairly low, as in a mercury vapor lamp with glass container, of Cooper-Hewitt type, rather than approaching an atmosphere as in a mercury vapor lamp in a quartz container. Surrounding the heater element is provided a tubular support or sleeve on which electrically separated layers of an electron emission material which may be termed the cathodes, are disposed.

Any suitable electron material may be employed. For example the surface of the sleeve may have layers or coatings composed of'a quick drying binder such as amyl acetate with the carbonates of the alkali earth metals. The carbonates being stable in the atmosphere, are stored for indefinite periods without detrimental effects. After the cathode has been assembled and mounted, the, carbonate coating is converted to the oxides of. the alkaline earth metals, by heating the cathode to a sufiiciently high temperature in the usual manner.

In the compartment containing the cathodes, are disposed a pair of anodes connected to opposite sides of the lamp circuit. The space relation between the cathodes and the anodes is relatively great, and in order to promote the glow discharge between the cathodes and anodes,

a starting anode is employed in close relation to the cathodes so that as the heater element raises the cathodes to an electron emitting temperature, an electron stream between the oathodes and the starting anode will ionize the gas which gradually spreads within the compartment until a free discharge occurs between the operating anodes and cathodes, causing a flow of current which persists when once started.

Obviously the operation of the starting anode is continuously available in the event that the discharge between the operating anodes and cathodes. decreases, in which case the starting anode functions to ionize the gas and again promote the discharge between the operating anodes and cathodes.

By reason of the present arrangement, the filaments employed for furnishing a light source,

obviously serve as a ballast resistance and may be so positioned as to radiate heat to vaporize the mercury in the compartment containing the glow discharge. i

The invention will be more clearly understood by referring to the following description together with the accompanying drawings in which,

Fig. 1 is a vertical sectional view of a combined illuminating and ultra-violet lamp constructed in accordance with the present invention;

Fig. 2 is a detail view of a cathode assembly for use in a lamp such as shown in Fig. 1 and Fig. 3 is a vertical sectional view of a modified form of the lamp shown in Fig. 1.

As shown in the drawings the selected embodiment of the invention may comprise a unit l6 having an inner chamber ii and outer chamber l2. The chambers may be disposed on a common axial line and the inner chamber may be provided with a reentrant tube I3, including a so-called tipless exhaust tube I4, and a press l5 in which conductors l6 and H are extended for connection to an alternating source of electrical energy (not shown).

Within the chamber II, and connected to conductors 6 and I1, are anodes l8 and i9 respectively. The chamber I is of elongated form and the anodes are positioned near an end 2| thereof. An opposite end 22 is provided with a pedestal 23 comprising a press 24 in which conductive support wires 25 and 26 are embedded.

The support wires 25 and 26 extend into the outer chamber l2 and are respectively connected to filaments 21 and 28 of the coiled type, which filaments are connected with conductors 29 and 36 passing through the wall of the inner chamber and connected to conductors I6 and H. The outer chamber |2 may be so formed as to enclose the greater portion of the chamber I and sealed thereto at 3| and may be exhausted through an aperture which is closed, after the exhausting operation, by a tip 32.

Within the inner chamber is a duplex cathode assembly 33 comprising a sleeve 33' of insulative material, such as lava or porcelain, having end plugs 34 and 35. Adjacent to each end of the sleeve are metallic casings 38' and 39' carrying layers or deposits 36 and 31 of electron emission material which may be considered as the cathodes proper. Within the sleeve are rods 38 and 39 which extend through the end plugs and support a heater element 46, preferably of a coiled tungsten wire. The ends of the heater element are connected to-the support rods 38 and 39, which in turn are connected to portions 4| and 42' of the conductors 25 and 26 respectively. The layer 36 of electron emission material is connected to portion 4| by a connector 43', and the layer 31 is connected to portion 42' by connector 44'. The casings 38 and 39', on which the electron emission material is deposited, are connected by means of conductors 43' and 44' to portions 4| and 42 of the conductors 25 and 26. Adjacent to the cathode 33 is a starting anode 4| supported on a conductor 42 passing through the press 24 and connected to the conductor 36.

A relatively high resistance element 43 is provided The filament wattage may be 100 and the discharge wattage about 200. Electrical current will pass through conductors l6 and 36, filament 28, conductor 26, heater element 46, conductor 25, filament 21 conductor 29 and conductor l1. Thus the filaments 21 and 28 will be rendered incandescent and the temperature 01' the heater element raised to heat the cathodes 36 and 31 to an emitting temperature.

When electrons are emitted they travel to the anode 4| upon which a potential is impressed and ionize the mercury vapor causing a local discharge or glow which increases as the filaments heat the mercury pool 44. As the glow increases ionization begins to take place between operating anode l9 and the cathode surfaces 38 and 31 and between operating anode l8 and the cathode surfaces 36 and 31 alternately when on an A. C. line.

Although the cathode shown in Fig. 1 may be preferable for alternating current on account of symmetry and in avoiding over-heating of the filament, it is to be understood that the said cathode may also be used on direct current. When using direct current a single cathode structure45 may be used, however, such as shown in Fig. 2. This cathode includes a conductive sleeve 46 having thereon a layer of electron emission material 41. The ends of the sleeve are provided with plugs 48 and 49 in which support rods 56 and 5| are disposed. A heater element orv coil 52 is connected at its ends to the support rods and conductors 53 and 54 extend through a press 55 and are secured to the said support rods. A starting anode 46' may be provided having a supporting conductor 41'. With this construction of cathode a device of the present character may be operated on direct current and a single anode such as anode l8 may be employed.

The present invention of combining a source of ultra-violet light with a source of illumination in a unitary structure lends itself to various modifications as for example a double envelope may be made such as that shown in Fig. 3 comprising an outer compartment 66 and an inner compartment 6|. The inner compartment may be provided with a reentrant tube 62 having an exhaust tube 63 and a press portion 64. Leading in conductors 65 and 66 may extend from the exterior of the compartment and through the press 64. The opposite end of the compartment 6I may be provided with a pedestal 61 having conductive support members 68 and 69, passing therethrough. A filament 16 may be connected between leading in conductor 65 and support 68 and a filament 1| may be connected between leading in conductors 66 and support 69.

The inner compartment may serve as the envelope for the light giving elements 16 and 1| while the outer compartment 66 may serve as the envelope for the glow discharge. A pool of mercury 12 may be disposed in the compartment 66 after it has been sealed at 13. to a wall of the compartment 6|. The mercury may be poured into the compartment 66 through an aperture which is closed after the exhausting opera tion, by the tip 14. Anodes 15 and 16 may be positioned in the compartment 66 and supported on conductive members 11 and 18 respectively. These members may pass through and be sealed in the wall of the compartment 6| and are connected to the leading in conductors 65 and 66.

Portions 19 and 86 of conductive supports 68 and 69, which extend into the compartment66,

not cease when the main discharge starts.

The starting anode may also function to maintain the glow in the event that the glow discharge decreases to such degree as not to produce a suficient flow of current from cathode to anode.

The operation of the embodiment of my inven tion illustrated in Fig. 1, when connected with a commercial A. C. line, is desirably as follows. Electrical energy will now through the leading in conductor l6, filament 28 which becomes incandescent and acts as a source of illumination, thence through heater element 40, filament 21, which also functions as alight source, and conductor ii. The heater element being enclosed-in the sleeve 33' heats the sleeve and the surfaces I or cathodes 36 and 31 are rendered thermionically active. The space relation between the cathodes and the anodes I 8 and I9 is however relatively large and it has been found desirable to provide means for producing an initial ionization of the gas to promote and maintain a discharge between the anodes and cathodes. This is accomplished by means comprising the starting anode ll disposed in close relation to the cathodes. As electrons flow from the cathodes tothe anode, 4| the gas becomes ionized and a glow appears which soon increases and fills a suflicient amount of the space between the cathodes and the anodes l8 and ill to bring about a glow discharge which increases until the inner compartment is filled and a substantial flow of current takes place between the operating elements of the device.

The resistance 43 serves to check the fiow of electrical energy to the anode M. m

The modification shown in Fig. 3 is operable in a manner similar to that described for Fig. l and, as will be evident, the filaments I0 and H which serve as the source of illumination will be enclosed in the glow discharge taking place in the compartment 60. This construction although detracting somewhat from the efliciency of the light source gives an efiective and beneficial result. It provides a unit of pleasing appearance for use in living rooms or the like, and

is useful as a source of illumination imitating daylight for the examination of colored objects.

Although a preferred embodiment of the invention is shown and described herein it is to be understood that modifications may be made without departing from the spirit and scope of the invention as set forth in the following claims:

I claim:

1. A combined ultra-violet and illuminating unit comprising a sealed envelope having two chambers, an electron emissive cathode and an anode in one chamber, mercury vapor surrounding said anode and cathode, means forheating said cathode to cause an electron flow ionizing said vapor to produce a glow discharge, an electrical circuit including said last mentioned means and a filament in series in saidcircuit.

2. A combined ultra-violet and illuminating unit comprising a sealed envelope having an inner and an outer chamber, a source of electrical energy, an electrical circuit including a filament in said outer chamber and the heater element of a cathode in said inner chamber,- said filament and heater element being in series, thermionically active material on said cathode, a gaseous environment in said inner chamber, an anode in 1 said inner chamber, means for ionizing the gas in said chamber to start an initial ionization of the gas in said chamber to promote a discharge between said anode and cathode.

3. A combined ultra-violet and illuminating unit comprising a sealed envelope having an inner and an outer chamber, a source of electrical energy an electrical circuit including a filament in said outer chamber and the heater element of a cathode in said inner chamber, said filament and heater element being connected in series, thermionically active material on said cathode, a gaseous environment in said inner chamber and an anode in said inner chamber, means for ionizing the gas in said chamber to start an initial ionization of the gas in said chamber to promote a discharge between said anode and cathode and means for rendering said last mentioned means temporarily inactive.

4. A combined ultra-violet and illuminating unit comprising a sealedcontainer having two concentrically disposed compartments, an electrical circuit, said circuit including a filament disposed in one compartment and a heater element in the other compartment, said filament and heater being connected in series, a cathode of a thermionically active material disposed in effective relation to said heater element, a gaseous environment about said material and an anode in said second mentioned compartment electrically connected to said circuit.

5. A combined ultra-violet and illuminating unit comprising a sealed container having two concentrically disposed compartments, an electrical circuit, said circuit including a filament disposed in one compartment and a heater element in the other compartment, said filament and heater being connected in series, a cathode of thermionically active material disposed in effective relation to said heater element, a gaseous environment about said material, an anode in said second mentioned compartment electrically connected to said circuit, and means for causing an initial ionization of the gas in said second mentioned envelope to promote a discharge between said cathode and anode.

6. An electrical device comprising a sealed envelope having two compartments, one of said compartments containing an ionizable medium, an indirectly heated cathode and an anode, the Other compartment containing a filament and means for connecting said cathode and said filament in series.

7. A combined ultra-violet and illuminating unit comprising a sealed envelope having two chambers, one of said chambers containing an ionizable gas and a thermionically active body, a heater element for rendering said body electrnn emissive. the other compartment having a plurality of filaments and means for connecting said heater elements and filaments in series.

8. An electrical device comprising a sealed envelope having two compartments, a cathode including a heater element and an anode in one compartment, anionizable environment for said anode, a filament in the other compartment, and means within said envelope electrically connecting said filament with said heater element for supplying energy thereto.

9. An electrical device comprising a sealed enmedium, a pair of anodes and an indirectly heated cathode in one of said compartments, a filament in the other compartment, and an electrical conductor within said envelope connecting said cathode and filament in series.

10. An electrical device comprising a sealed envelope having adischarge chamber and an incandescent filament chamber, an indirectly heated cathode, a pair of anodes and an ionizable medium in said discharge chamber, an incandescent filament in said filament chamber and electrical conductors connecting the heater element of said cathode in series with said anodes.

11. An electrical device comprising a sealed envelope having a discharge chamber and an incandescent filament chamber, an indirectly heated cathode, a pair of anodes and an ionizable medium in said discharge chamber, an incandescent filament in said filament chamber and electrical conductors within said envelope connecting the heater element of said cathode in series with said anodes and said filament.

12. An electrical device comprising a sealed envelope having an outer chamber and an inner chamber, a pair of conductive members extending into one end of said inner chamber, an indirectly heated cathode within said inner chamber connected to said conductive members, another pair of conductive members extending into the oppo site end of said inner chamber, an anode connected to each of said last named conductors,

' an ionizable medium in said inner chamber, a

filament in said outer chamber and means for connecting said filament in series with said cathode.

13. A discharge device comprising a sealed envelope having a gaseous filling and comprising a, plurality of electrodes, one of said-electrodes consisting of a heater element functioning at all times during operation of the device to supply heat to the electrode, and a thermionically active material so disposed as to be heated to electron emission .temperature by said heater element and means for connecting another of said electrodes and said heater element in series with a lightgiving filament for the passage of electrical energy therethrough to produce a glow discharge between said electrodes and supplement the energy radiated therefrom by the light from said filament.

14. A device for producing ultra-violet radiations comprising a sealed envelope transparent to ultra-violet light, said envelope containing a medium ionizable to produce ultra-violet light, a plurality of electrodes in said envelope, at least one of said electrodes including a thermionically active material, a heater element to render said material electron emissive to ionize said m'edium, electrical connection between said heater element and said material and means connecting said heater element and at least one of said other electrodes in series.

15. An electric lamp comprising in combination, two sealed bulbs of refractory'material, one contained within the other, one of said bulbs containing an ionizable medium anda pair of solid electrodes for passage of an arc therebetween including an electrical heating means for heating at least one of said electrodes, said other bulb containing an incandescible filament.

16. An electric lamp comprising in combination two sealed envelopes of refractory material, one

contained within the other, an incandescible means including a hot filament, and are means including an ionizable medium and a pair of solid electrodes for the passage of an are thereviolet radiation down to the short wave length limit of natural sunlight, an incandescible means including a, hot filament, are means including an ionizable medium radiating in the ultra-violet region of the spectrum and a pair of solid electrodes for the passage of an arc therebetween, at least one of said electrodes being electrically heated, and a pair of lamp terminals, said hot filament being connected in a closed circuit conmeeting said terminals and said electrodes being in electrical connection with said circuit to supply current for the are, one of said envelopes containing said electrode means and ionizable medium and said other envelope containing said hot filament.

18. An electric lamp comprising in combination two sealed envelopes of refractory, material, one contained within the other, an incandescible means including a hot filament, arc meanssincluding an ionizable medium and pair of solid electrodes for the passage of an arc therebetween, at least one of said electrodes including a refractory electron-emissive material and being electrically heated, and apair of lamp terminals, said hot filament being connected in a closed circuit connecting said terminals and said electrodes having electrical connection with said circuit to supply current for the arc, one of said envelopes one of said, envelopes containing said electrode means and ionizable medium and said other envelope containing said hot filament.

20. An electric lamp comprising a sealed envelope and a wall merging therewith and forming a compartment outside of said envelope, incandescible filament means in said envelope, and a plurality of electrodes in an ionizable medium in said compartment, one of said electrodes serving as a cathode and comprising a resistance for heating it to electron-emissive temperature, said resistance being connected to approximately the midpoint of said filament means, and another electrode connected to one of the outer terminals of said filament means in order to serve as an anode for a discharge from said cathode, with the filament means acting as a ballast.

CHARLES F. LORENZ.

DISCLAIMER 2,082,963.-0harles F. Lorenz, East Oren e, N. J. ULTRAVIOLET LAMP. Patent dated June 8, 1937. Disdaimer ed November 2, 1940, by the assignee,

Westinghouse Electric &2 Manufacturing Company. Hereby enters this disclaimer to claim 13 of the aforesaid patent.

[Oflimhl Gazette December 24, 1940.1 

